LEA-M8S / LEA-M8T - Hardware Integration Manual
UBX-13003140 - R07
Production Information
Design
Page 12 of 31
Setup for best performance with passive antenna
Figure 8 shows a design using an external LNA to increase the sensitivity for best performance with passive
antenna.
Figure 8: Module design with passive antenna and an external LNA (for exact pin orientation see the LEA-M8S Data Sheet [1]
and the NEO/LEA-M8T Data Sheet [2].)
The
VCC_RF
output can be used to supply the LNA with a filtered supply voltage.
For recommended parts, see Appendix
A standard GNSS LNA has enough bandwidth to amplify GPS / GLONASS and BeiDou signals.
2.4.2
Active antenna design
Active antennas have an integrated low-noise amplifier. Active antennas require a power supply that will
contribute to the total GNSS system power consumption budget with additional 5 to 20 mA typically.
If the customers do not want to make use of the internal antenna supervisor and the supply voltage of the LEA-
M8S / LEA-M8T module matches the supply voltage of the antenna (e.g. 3.0 V), they can use the filtered supply
voltage
VCC_RF
output to supply the antenna (See Figure 9). This design is used for modules in combination
with active antenna.
In case of different supply voltage, use a filtered external supply, see Figure 10.
Active antenna design using VCC_RF pin to supply the active antenna
Figure 9: Active antenna design, external supply from VCC_RF (for exact pin orientation see the LEA-M8S Data Sheet [1])
